The TGRC developed a set of introgression lines (ILs) representing the genome S. lycopersicoides LA2951 in the background of cv. VF36 (LA0490) Each line contains one to several alien chromosome segments, identified by markers (see map below). Most are available as homozygous stocks, but some must maintained via heterozygotes due to sterility. This resource consists of a ‘primary set’ of 56 lines that provide maximum genome coverage and homozygosity, and a ‘secondary set’ of 34 lines with additional segments representing different recombination breakpoints for greater map resolution. Together the lines cover about 96% of the map units in the tomato genome.

Many of the lines have reduced fertility, and will generally set fruit better under greenhouse conditions. Manual self pollination is recommended in these cases to insure seed set. Progeny of heterozygotes typically produce a deficiency of plants homozygous for the introgressed segments – and often a relative lack of heterozygotes as well – so population sizes should take this into account.

For some lines our seed supply is so limited that only small seed samples can be provided.